排序方式: 共有119条查询结果,搜索用时 15 毫秒
111.
Room‐temperature ring opening of various epoxides with aromatic thiols was carried out in water in the absence of any Lewis acid or additive. High yields of β‐hydroxy sulfides with excellent regioselectivity were obtained under very environmentally friendly conditions. 相似文献
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Tppz (2,3,5,6-tetrakis(2-pyridyl)pyrazine) complexes [Rh(tppz)(bpy)Cl][PF6]2.acetylacetone (bpy = 2,2′-bipyridine) and [{CdCl2}2(μ-tppz)].ethylene glycol have been synthesized and characterized by elemental analyses, IR, 1H NMR, cyclic voltammetry, photoluminescence and electronic spectral studies. Solid state structures of both complexes have been determined by single-crystal X-ray crystallography. The structural determination shows that the dinuclear Cd(II) complex, [{CdCl2}2(μ-tppz)], is a 1D coordination polymer. An ORTEP drawing of [Rh(tppz)(bpy)Cl][PF6]2.acetylacetone shows that the coordination geometry around the Rh(III) center is a distorted octahedron. [{CdCl2}2(μ-tppz)] displays intraligand 1(π–π*) fluorescence and can potentially serve as a photoactive material. For the mononuclear Rh(III) complex, only a two-electron reduction process occurs at the metal with the elimination of Cl− ligand. The emission of this complex is assigned as πd* phosphorescence. 相似文献
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Structural Chemistry - Kinesin Eg5 plays an essential role in the early stages of mitosis, and it is an interesting drug target for the design of potent inhibitors. In this work, combined molecular... 相似文献
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Fatemi FK 《Optics letters》2002,27(18):1637-1639
Frequency-resolved optical gating is used to characterize ultrashort optical pulses that are compressed nonadiabatically in dispersion-decreasing fiber. The pulses undergo an interesting temporal pulse breakup following dispersion in both the normal and anomalous regimes, and compression ratios close to the adiabatic limit are obtained. All behaviors are in excellent agreement with numerical integration of the nonlinear Schr?dinger equation. 相似文献
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Zhu H Ahmidouch A Anklin H Arenhövel H Armstrong C Bernet C Boeglin W Breuer H Brindza P Brown D Bültmann S Carlini R Chant N Cowley A Crabb D Danagoulian S Day DB Eden T Ent R Farah Y Fatemi R Garrow K Harris C Hauger M Honegger A Jourdan J Kaufmann M Khandaker M Kubon G Lichtenstadt J Lindgren R Lourie R Lung A Mack D Malik S Markowitz P McFarlane K McKee P McNulty D Milanovich G Mitchell J Mkrtchyan H Mühlbauer M Petitjean T Prok Y Rohe D Rollinde E Rondon OA Roos P Sawafta R Sick I Smith C 《Physical review letters》2001,87(8):081801
We report the first measurement using a solid polarized target of the neutron electric form factor G(n)(E) via d-->(e-->,e(')n)p. G(n)(E) was determined from the beam-target asymmetry in the scattering of longitudinally polarized electrons from polarized deuterated ammonia ( 15ND3). The measurement was performed in Hall C at Thomas Jefferson National Accelerator Facility in quasifree kinematics with the target polarization perpendicular to the momentum transfer. The electrons were detected in a magnetic spectrometer in coincidence with neutrons in a large solid angle segmented detector. We find G(n)(E) = 0.04632+/-0.00616(stat)+/-0.00341(syst) at Q2 = 0.495 (GeV/c)(2). 相似文献
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Samira Mehravar Shohreh Fatemi Masaharu Komiyama 《Surface and interface analysis : SIA》2020,52(9):547-552
Nickel supported on reduced graphene oxide was synthesized by chemical vapor deposition technique. The crystal structure and magnetic properties of the prepared sample were studied by means of Raman spectrometry, X-ray photoelectron spectroscopy (XPS), transmission electron microscopy (TEM), inductively coupled plasma optical emission spectrometry (ICP-OES), and vibrating sample magnetometry (VSM). The result of Raman spectroscopy revealed the structure of few-layer graphene as the support for Ni nanoparticles. XP spectrum confirmed the presence of metallic Ni on the a few-layer graphene surface. TE micrograph showed that the nickel nanoparticles were sphere shaped and the mean particle size is about 20 nm deposited on the reduced graphene oxide. The magnetic study showed the ferromagnetic behavior of 3.2 wt% nickel over reduced graphene oxide at room temperature. 相似文献
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Complex [Zn(Tppz)Cl2] (I), where Tppz = 2,3,5,6-tetrakis(2-pyridyl)pyrazine, has been synthesized and characterized by elemental analyses, IR, 1H NMR, cyclic voltammetry, and electronic spectral studies. Solid state structures of the complex have been determined by single-crystal X-ray crystallography. The structural determination shows that the mononuclear complex I is a 1D coordination polymer. Also an ORTEP drawing of complex I shows that the coordination geometry around the Zn(II) center is slightly distorted from regular square-based pyramidal. Crystal data for I: triclinic, spase group P $ \bar 1 $ , a = 10.171(2), b = 10.3550(13), c = 12.239 (2) Å, α = 64.839(9)°, β = 85.736(8)°, γ = 77.842(10)°, V = 1140.3(4) Å3, Z = 2. 相似文献